Pass by ref. A work around?

Hello,

I'm horrified to learn that in Java all variables are passed to methods by value.
I want to write a function that will fit an exponential function(y = A*exp(B*x) ) to some data. In C++ I would just pass the data along with references to variables for A and B to a method and have the method manipulate A and B.

In java it seems I need to have two different methods; one to return A and one to return B.